title: Isolation and partial characterization of cyclosporin synthetase from a cyclosporin non-producing mutant of Beauveria nivea.
abstract: Cyclosporin synthetase was isolated from a cyclosporin non-producing mutant of Beauveria nivea, strain YP 582. The enzyme has a molecular mass in the range of active cyclosporin synthetase and also contains 4'-phosphopantetheine as a prosthetic group. It is able to activate all constituent amino acids of cyclosporin A as thioesters and to carry out specific N-methylation reactions. Overall synthesis of the undecapeptide cyclosporin A in the presence of all necessary substrates was not observed, but the formation of the diketopiperazine cyclo-(D-alanyl-N-methyl-leucyl). This diketopiperazine represents a partial sequence of the cyclosporin molecule. It could be detected in the mycelium of the non-producing strain, whereas mycelium of the producing strain 7939/45 did not contain this compound. The results suggest that the inability of this mutant to produce cyclosporin A is caused by a mutation of the polypeptide chain of cyclosporin synthetase.
authors.affiliation: Institut für Biochemie und Molekulare Biologie, TU Berlin.
authors.forename: J
authors.initials: J
authors.lastname: Dittmann
authors.forename: A
authors.initials: A
authors.lastname: Lawen
authors.forename: R
authors.initials: R
authors.lastname: Zocher
authors.forename: H
authors.initials: H
authors.lastname: Kleinkauf
mesh_terms: D000595:Amino Acid Sequence; D003524:Cyclosporins / Q000096:biosynthesis; D005658:Fungi / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D008745:Methylation; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000302:isolation & purification* / Q000378:metabolism; D009154:Mutation; D010204:Pantetheine / Q000031:analogs & derivatives / Q000032:analysis / Q000302:isolation & purification; D010453:Peptide Synthases / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D003524:Cyclosporins; D009097:Multienzyme Complexes; C048525:cyclosporin A synthetase; D010204:Pantetheine; D010453:Peptide Synthases; C003129:4'-phosphopantetheine